First, I'm very new to python and this college class I took has been very unhelpful so sorry in advance.
I have a text document with book names. I need to make the user input an option. Each option coinsides with either displqaying the text document, editing the text document, or just stopping the program. I have the last
one. I can display it out of a loop. But, if I try to do it in a loop It jsut doesn't do anything, no error, just nothing.
f = open("Books.txt")
for line in f:
print (line)
inp = ()
while inp != 3:
print("1 - Display, 2 - Add, 3 - Exit")
inp = input("Please select an option.")
inp = int(inp)
if inp == 1:
print (f)
You can do this by using tell() and seek() methods with file object (f)
Here is the code for it
f = open("Books.txt", "a+")
inp = 0
while inp != 3:
print("1 - Display, 2 - Add, 3 - Exit")
inp = input("Please select an option.")
inp = int(inp)
if inp == 1:
if f.tell() != 0:
f.seek(0)
for line in f:
if line.strip():
print (line.strip())
elif inp == 2:
book = input("What is your book name? ")
f.writelines(["\n"+book])
f.close()
The output of this is as follows
1 - Display, 2 - Add, 3 - Exit
Please select an option.1
HELLO
WORLD
TEST
1 - Display, 2 - Add, 3 - Exit
Please select an option.2
What is your book name? Test2
1 - Display, 2 - Add, 3 - Exit
Please select an option.1
HELLO
WORLD
TEST
Test2
1 - Display, 2 - Add, 3 - Exit
Please select an option.3
Code explanation as follows
Open the file with append mode with readable access (https://docs.python.org/3/library/functions.html#open)
The file cursor will be at EOF (End of File) in this case so you can easily append the new text to the file
When the input is 1 we first check the cursor location using tell() which returns the integer value of the number of bytes read and if it's not in the starting. We move the cursor at starting of the file using seek(0) (https://docs.python.org/3/tutorial/inputoutput.html)
Since there are could be empty lines containing only new line characters which we can filter out while printing and later print the text by again stripping off the white characters using the strip() method on the string because the print function automatically adds new line character
To write the line we need to pass a new character (line separator of course) and then the input name of the book
f = open("Books.txt", "r+")
inp = 0
while inp != 3:
print("1 - Display, 2 - Add, 3 - Exit")
inp = input("Please select an option.")
inp = int(inp)
if inp == 1:
for line in f:
print (line)
elif inp == 2:
book = input("What is your book name? ")
f.writelines(["\n"+book])
f.close()
exit()
Related
I have created a program where I have two text files: "places.txt" and "verbs.txt" and It asks the user to choose between these two files. After they've chosen it quizzes the user on the English translation from the Spanish word and returns the correct answer once the user has completed their "test". However the program runs smoothly if the text files are free in the folder for python I have created on my Mac but once I put these files and the .py file in a subfolder it says files can't be found. I want to share this .py file along with the text files but would there be a way I can fix this error?
def CreateQuiz(i):
# here i'm creating the keys and values of the "flashcards"
f = open(fileList[i],'r') # using the read function for both files
EngSpanVocab= {} # this converts the lists in the text files to dictionaries
for line in f:
#here this trims the empty lines in the text files
line = line.strip().split(':')
engWord = line[0]
spanWord = line[1].split(',')
EngSpanVocab[engWord] = spanWord
placeList = list(EngSpanVocab.keys())
while True:
num = input('How many words in your quiz? ==>')
try:
num = int(num)
if num <= 0 or num >= 10:
print('Number must be greater than zero and less than or equal to 10')
else:
correct = 0
#this takes the user input
for j in range(num):
val = random.choice(placeList)
spa = input('Enter a valid spanish phrase for '+val+'\n'+'==> ')
if spa in EngSpanVocab[val]:
correct = correct+1
if len(EngSpanVocab[val]) == 1:
#if answers are correct the program returns value
print('Correct. Good work\n')
else:
data = EngSpanVocab[val].copy()
data.remove(spa)
print('Correct. You could also have chosen',*data,'\n')
else:
print('Incorrect, right answer was',*EngSpanVocab[val])
#gives back the user answer as a percentage right out of a 100%
prob = round((correct/num)*100,2)
print('\nYou got '+str(correct)+' out of '+str(num)+', which is '+str(prob)+'%'+'\n')
break
except:
print('You must enter an integer')
def write(wrongDict, targetFile):
# Open
writeFile = open(targetFile, 'w')
# Write entry
for key in wrongDict.keys():
## Key
writeFile.write(key)
writeFile.write(':')
## Value(s)
for value in wrongDict[key]:
# If key has multiple values or user chooses more than 1 word to be quizzed on
if value == wrongDict[key][(len(wrongDict[key])) - 1]:
writeFile.write(value)
else:
writeFile.write('%s,'%value)
writeFile.write('\n')
# Close
writeFile.close()
print ('Incorrect answers written to',targetFile,'.')
def writewrong(wringDict):
#this is for the file that will be written in
string_1= input("Filename (defaults to \'wrong.txt\'):")
if string_1== ' ':
target_file='wrong.txt'
else:
target_file= string_1
# this checs if it already exists and if it does then it overwrites what was on it previously
if os.path.isfile(target)==True:
while True:
string_2=input("File already exists. Overwrite? (Yes or No):")
if string_2== ' ':
write(wrongDict, target_file)
break
else:
over_list=[]
for i in string_1:
if i.isalpha(): ovrList.append(i)
ovr = ''.join(ovrList)
ovr = ovr.lower()
if ovr.isalpha() == True:
#### Evaluate answer
if ovr[0] == 'y':
write(wrongDict, target)
break
elif ovr[0] == 'n':
break
else:
print ('Invalid input.\n')
### If not, create
else:
write(wrongDict, target)
def MainMenu():
## # this is just the standad menu when you first run the program
if len(fileList) == 0:
print('Error! No file found')
else:
print( "Vocabulary Program:\nChoose a file with the proper number or press Q to quit" )
print(str(1) ,"Places.txt")
print(str(2) ,"Verbs.txt")
while True:
#this takes the user input given and opens up the right text file depending on what the user wants
MainMenu()
userChoice = input('==> ')
if userChoice == '1':
data = open("places.txt",'r')
CreateQuiz(0)
elif userChoice == '2':
data = open("verbs.txt",'r')
CreateQuiz(1)
elif userChoice == 'Q':
break
else:
print('Choose a Valid Option!!\n')
break
You are probably not running the script from within the new folder, so it tries to load the files from the directory from where you run the script.
Try setting the directory:
import os
directory = os.path.dirname(os.path.abspath(__file__))
data = open(directory + "/places.txt",'r')
My code does not write to a file, what am I doing wrong? I am trying to program to continue to ask for products until the user does not enter a product code. I want all products to be saved in the file.
store_file = open("Database.txt", "w")
NewProduct = ""
while NewProduct != False:
contine = input("Press 1 to enter a new product press 2 to leave: ")
if contine == "1":
print("Enter your product information")
information = []
product = input("What's the product code: ")
information.append(product)
description = input("Give a description of the product: ")
information.append(description)
price = input("Enter price of product: ")
information.append(price)
information = str(information)
clean = information.replace("]","").replace("[","").replace(",","").replace("'","")
store_file.write(clean)
elif contine == "2":
NewProduct = False
else:
print("Your input is invalid")
store_file.close
I got the program working with the following adjustments. See comments for explanations:
store_file = open("Database.txt", "w")
NewProduct = ""
while NewProduct != False:
continue = raw_input("Press 1 to enter a new product press 2 to leave: ")
#Changed to raw_input because input was reading in an integer for 1 rather than a
#string like you have set up. This could be specific to my IDE
if continue == "1":
print("Enter your product information")
information = []
product = raw_input("What's the product code: ")
information.append(product)
description = raw_input("Give a description of the product: ")
information.append(description)
price = raw_input("Enter price of product: ")
information.append(price)
information = str(information)
clean = information.replace("]","").replace("[","").replace(",","").replace("'","")
store_file.write(clean + "\n")
#Added a line break at the end of each file write
elif contine == "2":
NewProduct = False
else:
print("Your input is invalid")
store_file.close() #Added parentheses to call the close function
I'm assuming the problem here is that you're using Python 2, and input isn't doing what you think it does. In Python 2, input evals the input as if it were Python source code, so if someone enters 2, it's going to return the int value 2, not "2". In Python 2, you want to use raw_input, always (eval-ing random user input not being secure/reliable).
Also, while on CPython (the reference interpreter) files tend to naturally close themselves when they go out of scope, you made an effort to close, but forgot to actually call the close method; store_file.close looks up the method without calling it, store_file.close() would actually close it. Of course, explicit close is usually the wrong approach; you should use a with statement to avoid the possibility of forgetting to close (or of an exception skipping the close). You can replace:
store_file = open("Database.txt", "w")
...
store_file.close()
with:
with open("Database.txt", "w") as store_file:
... do all your work that writes to the file indented within the with block ...
... When you dedent from the with block, the file is guaranteed to be closed ...
There are other issues though. What you're doing with:
information = str(information)
information = information.replace("]","").replace("[","").replace(",","").replace("'","")
is terrible. I'm 99% sure what you really wanted was to just join the inputs with spaces. If you switch all your input calls to raw_input (only on Python 2, on Python 3, input is like raw_input on Python 2), then your list is a list of str, and you can just join them together instead of trying to stringify the list itself, then remove all the list-y bits. You can replace both lines above with just:
information = ' '.join(information)
I am writing a program that will open a specified file then "wrap" all lines that are longer than a given line length and print the result on the screen.
def main():
filename = input("Please enter the name of the file to be used: ")
openFile = open(filename, 'r+')
file = openFile.read()
lLength = int(input("enter a number between 10 & 20: "))
while (lLength < 10) or (lLength > 20) :
print("Invalid input, please try again...")
lLength = int(input("enter a number between 10 & 20: "))
wr = textwrap.TextWrapper()
wr.width = lLength
wr.expand_tabs = True
wraped = wr.wrap(file)
print("Here is your output formated to a max of", lLength, "characters per line: ")
print(wraped)
main()
When I do this instead of wrapping it prints everything in the file as a list with commas and brackets, instead of wrapping them.
textwrap.TextWrapper.wrap "returns a list of output lines, without final newlines."
You could either join them together with a linebreak
print('\n'.join(wrapped))
or iterate through and print them one at a time
for line in wrapped:
print(line)
So I have a question that requires this The features : color,size,flesh and class are separated by spaces. Write a Python program that asks the user for the names of the input file (in this case animals.txt) and the output file (any name). The program reads in the lines of the input file, ignores comment lines (lines starting with #) and blank lines and computes and prints the answers to the following questions:
Total number of animals?
Total number of dangerous animals?
Number of large animals that are safe?
Number of animals that are brown and dangerous?
Number of safe animals with red color or hard flesh?
So I finished the program and everything seems to be working but so far when I enter the code and initiate the program, everything works, no errors, nothing but no output file gets generated. I don't know what is wrong exactly but if someone could point me in the right direction it would be highly appreciated.
import os.path
endofprogram = False
try:
filename1 = input("Enter the name of input file: ")
filename2 = input("Enter the name of output file: ")
while os.path.isfile(filename2):
filename2 = input("File Exists! Enter new name for output file: ")
infile = open(filename1, 'r')
ofile = open(filename2, "w")
except IOError:
print("Error reading file! Program ends here")
endofprogram = True
if (endofprogram == False):
alist = []
blist = []
clist = []
largesafe = 0
dangerous = 0
browndangerous = 0
redhard = 0
for line in infile:
line = line.strip("\n")
if (line != " ") and (line[0] != "#"):
colour, size, flesh, clas = line.split('\t')
alist = alist.append(colour)
animals = alist.count()
while clas == "dangerous":
dangerous = dangerous + 1
while size == "large" and clas == "safe":
largesafe = largesafe + 1
while colour == "brown" and clas == "dangerous":
browndangerous = browndangerous + 1
while colour == "red" and flesh == "hard":
redhard = redhard + 1
ofile.write(print("Animals = \n", animals))
ofile.write(print("Dangerous = \n", dangerous))
ofile.write(print("Brown and dangerous = \n", browndangerous))
ofile.write(print("Large and safe = \n", largesafe))
ofile.write(print("Safe and red color or hard flesh= \n", redhard))
infile.close()
ofile.close()
Your indentation has completely messed the program up. The biggest offender is this section:
except IOError:
print("Error reading file! Program ends here")
endofprogram = True
if (endofprogram == False):
The if line will only ever be executed right after the endofprogram = True line, at which point endofprogram == False will be false, and so nothing in the if block — which include the rest of the program — will be executed. You need to dedent everything from the if onwards by one level.
Maybe you can remove the print inside ofile.write
ofile.write(print("Animals = \n", animals))
to
ofile.write("Animals = \n" + str(animals))
fileName = raw_input("Enter the filename: ")
n = input("Enter the line you want to look: ")
f = open(fileName,'r')
numbers = []
for line in f:
sentenceInLine = line.split('\n')
for word in sentenceInLine:
if word != '':
numbers.append(word)
print numbers
print len(numbers)
print numbers[n-1]
if n == 0:
print "There is no 0 line"
break
i think you missed to split sentenceInLine like sentenceInLine.split(' ')
You are looping over each line, then you split lines based on '\n'. That \n is a line break character. That would confuse your logic right there.
So it is a bit confusing what you are trying to do but you should check n after the user has inputed a value for n. not at the end.
You may want to also catch the exception where file cannot be found I think this is what you need:
fileName = raw_input("Enter the filename: ")
n = input("Enter the line you want to look: ")
if n == 0:
print "There is no 0 line"
sys.exit();
try:
f = open(fileName,'r')
except IOError:
print "Could not find file"
sys.exit()